Aircraft powered by gas turbine engines radiate a large amount of infrared energy. The radiation is emitted both from the exposed hot metal engine parts and from the hot exhaust gas plumes. The radiated infrared energy makes a military aircraft vulnerable to a heat seeking missile. Much has been done by both the airframe and engine manufacturers in recent years to try to combat this vulnerability. The U.S. Pat. No. 4,007,587 to Banthin et al shows one approach used to suppress the infrared radiation from a gas turbine engine. In Banthin et al a vane assembly is attached to the tailpipe of a gas turbine engine used for driving the rotor of a helicopter. The vane assembly provides for the introduction of cooling air which serves to both dilute and cool the hot gas exhaust from the engine. At the same time, the vane assembly serves to shield from view the hot metal parts at the aft end of the turbine engine.
Numerous other infrared radiation suppressors have been tried. Many of these require the use of large air pumps or in some way necessitate a substantial engine power loss when operating. Our invention overcomes these deficiencies, providing a simple and efficient suppressor that can be easily incorporated into a bypass turbine engine.